Called when the desired version of a program is not registered with the RPC package. low_vers is the lowest version number, and high_vers is the highest version number. Service implementors usually do not need this routine.

void svcerr_systemerr(const SVCXPRT *xprt);

Called by a service dispatch routine when it detects a system error not covered by any particular protocol. For example, if a service can no longer allocate storage, it may call this routine.

void svcerr_weakauth(const SVCXPRT *xprt);

Called by a service dispatch routine that refuses to perform a remote procedure call due to insufficient (but correct) authentication parameters. The routine calls svcerr_auth(xprt, AUTH_TOOWEAK).